Variable-circuit element for radio receiving sets



March 11, 1930. RKVREELAND 1,749,930

VARIABLE CIRCUIT ELEMENT FOR RADIO RECEIVING SETS Filed April 15, 1926 ------1 I I I I l I l I I I I I E L"; i I E M I I I I l I l L...]

IIIIII IIIIIIIIIII Ill YEN TOR IHlllllllllllllllll IIHIIIIIIIIIIIllllllllllIIIIIIIIIIIIIIIIIIIII Patented Mar; lfl, 1 930 FREDERICK KQVREELAND, OF MONTGLAIB, NEW JERSEY I VARIABLE-CIRCUIT ELEMENT Application filed April 15,

In another application, Serial No. 680,061,

which the operations of tuning and compensating' are effected through the manipulation of certain mechanical devices which have been found to be of great practical value and adaptable as'well to the operation of variable circuit elements other than the variable capacities oif'that application. In the present application it is the intention to cover these mechanical devices in combination'with such a variable circuit element or frequency selective device, such, for example, as a condenser or a variable inductor. In accordance with the invention, there is placed within the panel or closure of the casing of the receiving set and preferably on an axis parallel with the panel, adisc or dial, the periphery of which, preferably having a scale marked thereon, is exposed to view through-an aperturein the panel, which may be glazed, and there is also operatively connected with the variable circult element andwith the first .mentioned disc or -dial, an operating device or hand wheel which'may be in the form of .a second disc or dial which may or may not have a scalemarked on the periphery thereof and which is preferably on a shaft also parallel with the panel and is exposedpr proj ects through'another aperture in the panel, presenting in the preferred embodiment at most a segmental portion only for manipulation from the front of the panel. I

The invention will be more fully described hereinafter with reference to the accompanying drawing which, as to the several figures presented,-is the 'same as the corresponding fi res. of the drawings of the application a ove mentioned'and in which; Figure 1 is a schematic diagram showing a simple embodiment of the invention described in the application above mentioned, with. the mechanical, devices herein particularly referred toincorporated therewith.

Fi re 2 is a'face view of a portion of the pane of a radio receiving set, partially .single motion, but it is exemplified in the operation of 'has a scale marked on its FOB RADIO RIIICEIVEIING' SETS 1926. serial No. 102,142.

broken out to show the said mechanical devices.

Figure 3 is a view of the same as seen from a point of view in a plane parallel with the panel which itself is shown in section.

It is not necessary, in the present case, to enter into any extended description of the radio circuits and related devices shown in Figure 1, it being suificient for present purposes to state that in the illustrated embodiment of the invention the variable circuit elements are represented as variable capacities C C the movable plates of which are mounted on alined shafts It and R preferallply parallel vaith the panel 0 or cllosure of t e casin an carr respective ears G G I %he latter i' e shown as' n iefin'ng' respectively with pinions P P on a counter shaft Q Q which in the embodiment shown is also parallel with the anel O and having an adjusting wheel or 'so N, which is exposed for manipulation by the finger through a slot 0 in the panel 0, preferably projecting somewhat through such slot, as shown in Figure 3, so as to facilitate manipulation. In the particular construction shown, both shafts R R are rotated simultaneously so that the elements C C are adjusted by'a obvious that so far present invention is concerned, it is a single element, such as the element 0 On the shaft R of'the'element C is a disc or dial M which periphery for cowhich, in the aras the operation with an index I rangement shown is a line on a transparent window I whic may close the aperture throu h which the dial is viewed and serve to exclude dust from the interior of the receiving set. The whole structure can be conveniently mounted within the panel or closure through which the operating device N is exposed and the disc or dial M is viewed. In the particular arrangement shown the peripheral edge exposed for convenient mam ulation throu h.- the aperture 0 and the sea e carried by t 0 disc or dial M is viewed through the aperture I. It will be obvious that the ed ewise arrangement ofthe disc or dial and o the operof the operating device N is 60 tur'e to indicate mounted adjacent tating said shaft exposed through one ofating device has great practical advantages, not only in convenience of arrangement and in protection against the entrance of dust Within the receiving set, but in the elimina tion from the outside of the panel of the usual dials parallel with the face of the panel.

I claim as my invention:

1. In a radio signaling system and in com-' bination with a pluralityof tunable circults,

variable instrulnentalities one at least thereof being included in each of said circuits for tuning said circuit, an instrument panel having apertures therethrough', a rotatable shaft said panel, means for rosai-d apertures of said anel, an indicating dial mounted onsaid s iaft and positioned opposite the other of said apertures 1n said panel, and connections between said shaft and said tuning elements whereby said tuning elements are simultaneously operated by said rotating means and said indicating dial is positioned opposite its aperture to indicatethe adjustment of said tuning elements,

when said shaft is rotated.

2'. In a radio signaling system and in combination with a plurality of tunable circuits, variable condensers one at least thereof being included in each of said circuits for tuning said circuit, an instrument panel having apertures therethrough, a rotatable shaft mounted adjacent said panel, means for rotating said'shaft exposed through one of said apertures of said panel, an indicating dial mounted on said shaft and positioned opposite the other of said apertures in said panel, and connections between said shaft and said tuning elements whereby said tuning elements are simultaneously operated by said rotating means and said indicating dial is positioned j opposite its aperture to indicate the adjustment of said tuning elements when said shaft is rotated.

3. a radio signaling system and in combmatlonwith a plurality of tunable circuits,-

variable instrumentalities one at least thereof meaeao being included in each of said circuits for tuning said circuit, an instrumentpanel hav-' ing apertures therethrough,

tatable shaft also mounted adjacent said panel and having an operating device exposed through one of said apertures, -mitting means between said shafts, an indicating dial'mounted on the first mentioned shaft and positioned opposite the other of said apertures in said panel, and connections between said shaft and said tuning elements whereby said tuning elements are simultaneously operated by said rotating means and said indicating dial is positioned opposite itsaperture to indicate the adjustment of said tuning elements when said shaft is rotated.

5. In a-ra'dio signaling system and in combination with a plurality of tunable circuits, variable instrumentalities one at least thereof being included in each of said circuits for tuning said circuit, an instrument panel hava rotatable shaft mounted adjacent said panel, a second ro-- trans.

dial is positioned opposite its aperture to indicate the adjustment of said tuning elements when said shaft is rotated.

This specification signed April A D. 1926.

I FREDERICK K. V'REELAND;

being included in each of said circuits for tuning said circuit, .an instrument panel having apertures 'therethrough, a rotatable shaft mounted within the. anel and parallel therewith 'in asubstantially horizontal plane,

' means for. rotating said shaft exposed throu h oneof said apertures of said' anel, an in 'cating dial mounted on said sha and positioned opposite thev other of said apertures in said panel, said shaft and said tuning'elements whereby said tuning elements are simultaneously operated by said rotating means and said indicating dial :is positioned opposite its aperthe. adjustment of said tuning elements when said shaft is rotated.

4. In a radio si aling system and in combination with a p urality oftunable circuits variable instrumentalities one at least thereof andconnections between I this 12th day of 

